Figure 5.

Interrogation of an RNA element within the p28 coding sequence by providing both p28 and p88 in trans. (A) Schematic depiction of the p28TS mutant replicon encoding neither p28 nor p88, with the positions of three stop codons shown. (B) The Basal RNA structure involving mostly p28 coding sequence. Note that this structure is mutually exclusive with RSE because, in this structure, the Fa element pairs with the Ff element (in blue letters) within the p28 coding sequence. Accordingly, the mA2 mutations shown in Figure 2 now disrupt the FfFa stem structure. Two additional mutants, mF2 and mF2A2, were also tested, along with a Ff deletion mutant (ΔF). All mutants were based on p28TS. (C) Northern blotting showed that, unlike earlier mutants, these mutants did not replicate in the presence of trans p88 alone. (D) Northern blotting revealed a modest role of Ff in TCV gRNA accumulation. (E) Quantification of Northern botting results of multiple repeat experiments.